661354690 has 16 divisors (see below), whose sum is σ = 1196674560. Its totient is φ = 263156080.

The previous prime is 661354667. The next prime is 661354691. The reversal of 661354690 is 96453166.

It is a super-2 number, since 2×661354690² = 874780051969992200, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (661354691) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 171220 + ... + 175039.

It is an arithmetic number, because the mean of its divisors is an integer number (74792160).

Almost surely, 2^661354690 is an apocalyptic number.

661354690 is a deficient number, since it is larger than the sum of its proper divisors (535319870).

661354690 is a wasteful number, since it uses less digits than its factorization.

661354690 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 346457.

The product of its (nonzero) digits is 116640, while the sum is 40.

The square root of 661354690 is about 25716.8172603065. The cubic root of 661354690 is about 871.2540553129.

The spelling of 661354690 in words is "six hundred sixty-one million, three hundred fifty-four thousand, six hundred ninety".